Wake up refreshed, not groggy. Time your nap and set the right alarm.
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Short naps of 10–20 minutes stay in light sleep, so you wake up alert. Naps of 30–60 minutes reach deep sleep, which helps memory but can leave you groggy for a while (sleep inertia). A 90-minute nap completes a full cycle, including REM sleep.
Pick when you will lie down and the kind of nap. The calculator sets your alarm, allowing time to fall asleep, shows your best nap window (the natural dip 7–9 hours after waking) and warns you if a nap is too close to bedtime.
| I will lie down at | 2:00 PM |
| Nap length | Power nap (20 min) |
| Minutes to fall asleep | 7 min |
| I woke up today at | 7:00 AM |
| I go to bed at | 11:00 PM |
| Set your alarm for | 2:27 PM |
| Nap | Power nap — 20 minutes of sleep |
| What it does | More alert without grogginess; best for a quick boost |
| Best nap time for you | 2:00 PM – 4:00 PM (the afternoon dip, 7–9 hours after waking) |
| Check | ✔ Good timing |
Alarm at 2:27 PM.
| I will lie down at | 4:00 PM |
| Nap length | Full cycle (90 min) |
| Minutes to fall asleep | 10 min |
| I woke up today at | 8:00 AM |
| I go to bed at | 2:00 AM |
| Set your alarm for | 5:40 PM |
| Nap | Full sleep cycle — 90 minutes of sleep |
| What it does | Includes REM sleep — helps creativity; wake up naturally refreshed |
| Best nap time for you | 3:00 PM – 5:00 PM (the afternoon dip, 7–9 hours after waking) |
| Check | ✔ Good timing |
5:40 PM.
10–20 minutes. NASA research on pilots found a 26-minute nap improved alertness by over 50% and performance by 34%.
You probably woke from deep sleep. Keep naps under 20 minutes or extend them to a full 90-minute cycle.
Early afternoon, about 1–3 PM for most people — and at least 6 hours before bedtime.